This invention relates generally to the field of superchargers as used with internal combustion engines and, more particularly, to a vaned device used to control air flow into a gasoline-powered internal combustion engine, which device operates to both provide energy to such engine during low throttle conditions, and to provide supercharged intake air to an engine during high throttle conditions.
Superchargers and turbochargers for gasoline and diesel internal combustion engines are known devices used in the art for pressurizing or boosting the pressure of an intake air stream that is routed to a combustion chamber of the engine. In a turbocharger, the boost air is provided by a compressor that is driven by the heat and volumetric flow of exhaust gas exiting the engine. In a supercharger, the boost air is provided by a compressor or gears that are driven by the engine crankshaft via one or more belts or gears. Because of the manner that superchargers are driven by the engine, a horsepower loss is incurred by their operation. However, the horsepower loss associated with driving the supercharger is more than offset by the horsepower increase provided by the supercharged intake air directed to the engine for combustion at full load conditions.
Thus, superchargers are driven by the engine crankshaft to rotate an internal member that causes the pressure of intake air directed to the engine to be boosted. When used with a gasoline-powered internal combustion engine, an increase in throttle operating condition results in greater pressurized air flow into the engine for combustion. A decrease or reduction in throttle operating condition causes a reduction in the amount of air flow into the engine.
During engine xe2x80x9cthrottlingxe2x80x9d, e.g., reduction of throttle position for purposes of vehicle speed control, the amount of air flow being directed to the engine is reduced, thereby reducing the operating efficiency of the engine. The reduction of operating efficiency during such throttling condition is referred to as xe2x80x9cthrottle loss,xe2x80x9d and is a well known occurring condition with gasoline-powered internal combustion engines. In supercharged engine systems, however, the operating efficiency of the engine during such throttling condition is further reduced/exacerbated due to the fact that the supercharger is simultaneously being driven by the engine, i.e., taking energy from the engine.
It is, therefore, desired that a device be constructed that is capable of both providing a desired degree of supercharging, i.e., providing a desired degree of intake air pressurizing, during on-throttle conditions, and minimize engine operating efficiency loss during off-throttle or throttling conditions, i.e., provide throttle loss recovery. It is desired that such a device be capable of being attached to an engine and/or within an engine compartment with a minimum amount of alteration when compared to conventional supercharger systems.
A throttle loss recovery turbine and supercharger device is constructed, according to the principles of this invention, for placement within an engine intake system replacing conventional means for controlling airflow for combustion. The device comprises a housing, that is generally cylindrical in shape, and that includes a movable intake (or air inlet) port and an exhaust (or air outlet) port that is movable independent of the intake port. In an example embodiment, the intake and exhaust ports are disposed through end plates that are attached to each axial housing end.
An outer rotary member or drum is rotatably disposed within the housing, and a plurality of bearings are interposed between an inside wall surface of the housing and an outside wall surface of the outer drum to facilitate outer drum rotation within the housing. An inner rotary member or drum is rotatably disposed within the housing and within an inside diameter of the outer drum. The inner drum has an axis of rotation that is eccentric to an axis of rotation of the outer drum, and the inner and outer drum are configured to rotate within the housing at a 1:1 ratio with one another. A variable volume annular space is defined within the housing between the inner and outer drums, and the intake and exhaust ports are each in air flow communication with some portion of the annular space;
The device comprises a number of vanes that are each interposed radially between the inner and outer drums. Each vane is pivotably attached at one of its ends to a portion of the outer drum. An opposite end of each vane is disposed within a portion of the inner drum outside diameter that is configured to facilitate reciprocating and pivoting movement of the vane end therein. The device includes a means for connecting at least one of said drums to an engine crankshaft.
When the engine is operated at a low load or idle throttle condition, the device is placed into a throttle loss recovery mode to generate and transmit power to the engine. The device does this by moving the intake port within the housing to a position adjacent a minimum of the annular volume space between the rotating drums, and moving the exhaust port within the housing to a position adjacent a maximum of the annular volume space. Placed in this configuration, air entering the device moves from a position of small volume to large volume, operating to effect rotation of the drums, which rotary energy is transmitted to the engine via the connecting means.
When the engine is operated at a high load or wide open throttle condition, the device is placed into a supercharger mode to generate pressurized air to the engine intake system for subsequent combustion. The device does this by moving the intake port within the housing to a position adjacent a maximum of the annular volume space between the rotating drums, and moving the exhaust port within the housing to a position adjacent a minimum of the annular volume space. Placed in this configuration, air entering the device moves from a position of large volume to small volume, operating to pressurize the air moving through the device, which pressurized air is routed to the engine for combustion.